Satellite communication terminals aboard various vehicles including ocean going vessels and land based units require stabilization of instrument platforms. Such operations take place in environments where motion of pitch and/or roll are present.
There are many instances where antennas and various instrumentation are required to be stabilized against motion disturbances encountered on moving vehicles. These applications include, but are not limited to, satellite antennas, microwave antennas, radar antennas, navigation equipment, cameras and various optical and positioning devices. The vehicles aboard which these systems might be used include commercial and military land vehicles, ships, aircraft and missiles.
There are two general types of vertical stabilization systems in use:
1. Closed loop servo systems which use servo motors, servo amplifiers, angular transducers and vertical references (usually small vertical gyros) to sense angular displacements of the vehicle and make the necessary corrections for each axis.
2. Direct mechanical stabilization systems, which use two or four large flywheel assemblies acting as direct-acting gyros. The following patents relate to direct mechanical stabilization systems:
U.S. Pat. No. 3,893,123 PA1 U.S. Pat. No. 4,020,491 PA1 U.S. Pat. No. 4,193,308 PA1 U.S. Pat. No. 4,197,548.